1. Field of the Invention
The present invention relates to a torsional vibration damper arrangement, especially for the drive train of a motor vehicle, having a primary side and a secondary side, the secondary side being connected to the primary side for rotation around an axis of rotation and for relative rotation of the two sides with respect to each other by a damper fluid arrangement, where, to transmit torque between the primary side and the secondary side, the damper fluid arrangement includes a first damper fluid of a first compressibility and a second damper fluid of a second compressibility greater than the first compressibility, the second damper fluid being put under load when the pressure of the first fluid increases.
2. Prior Art
A torsional vibration damper arrangement for the drive train of a motor vehicle in which torque is transmitted between a primary side and a secondary side by way of a first damper fluid of low or negligible compressibility, such as an oil, and a second damper fluid of comparatively high compressibility, such as air, is disclosed in DE 10 2005 018 954 A1. The damper fluid arrangement comprises two fluid chambers connected in series between the primary side and the secondary side and separated by a separating piston, one of these chambers being filled with the essentially incompressible fluid, the other with the compressible fluid. So that the damping characteristic can be influenced, the fluid chamber in which the compressible fluid is present is connected by a rotary leadthrough to a source of this pressurized compressible fluid such as air or some other gas. The problems here are that chambers for both fluids must be provided, one in the area of the primary side, the other in the area of the secondary side, and that a rotary leadthrough and the necessary seals for a gaseous fluid must be provided.
The subsequently published German Patent Application 10 2005 058 531.0 discloses a torsional vibration damper in which the transmission of torque occurs by way of series-connected fluid chambers, one of which contains a comparatively highly compressible fluid such as air, whereas the other contains an essentially incompressible fluid such as oil. A supply system operating by way of a rotary leadthrough is assigned to the volume area, i.e., to the chamber, which is filled with the incompressible fluid to change the pressure of this essentially incompressible fluid.